Answer: Option B
The sentence "I prefer chess __ carrom" is asking for a comparison between two things, and in this case, it is asking which game is preferred over the other. The word "prefer" indicates that the speaker has a choice between two options and is indicating a preference for one over the other.
The correct preposition to use in this sentence is "to", which is often used to show a comparison or a preference between two things.
The completed sentence would be: "I prefer chess to carrom."
In summary, the correct option to fill in the blank is "to".